/*
    Android Asynchronous Http Client
    Copyright (c) 2013 JIXIAOLONG <MicroJixl@gmail.com>

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
 */

package com.jxl.netframe.apachebase;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.http.util.EncodingUtils;

import com.jxl.netframe.log.Logger;

/***
 * This class implements a part of a Multipart post object that
 * consists of a file.  
 *
 * @author JiXL
 * @time 2013-5-27 下午5:37:37
 *
 */
public class FilePart extends PartBase {

	private static final String TAG = "com.jxl.netframe.apachebase.FilePart";

	/*** Default content encoding of file attachments. */
	public static final String DEFAULT_CONTENT_TYPE = "application/octet-stream";

	/*** Default charset of file attachments. */
	public static final String DEFAULT_CHARSET = "ISO-8859-1";

	/*** Default transfer encoding of file attachments. */
	public static final String DEFAULT_TRANSFER_ENCODING = "binary";

	/*** Attachment's file name */
	protected static final String FILE_NAME = "; filename=";

	/*** Attachment's file name as a byte array */
	private static final byte[] FILE_NAME_BYTES = 
			EncodingUtils.getAsciiBytes(FILE_NAME);

	/*** Source of the file part. */
	private PartSource source;

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name for this part
	 * @param partSource the source for this part
	 * @param contentType the content type for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CONTENT_TYPE default} is used
	 * @param charset the charset encoding for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CHARSET default} is used
	 */
	public FilePart(String name, PartSource partSource, String contentType, String charset) {

		super(
				name, 
				contentType == null ? DEFAULT_CONTENT_TYPE : contentType, 
						charset == null ? "ISO-8859-1" : charset, 
								DEFAULT_TRANSFER_ENCODING
				);

		if (partSource == null) {
			throw new IllegalArgumentException("Source may not be null");
		}
		this.source = partSource;
	}

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name for this part
	 * @param partSource the source for this part
	 */
	public FilePart(String name, PartSource partSource) {
		this(name, partSource, null, null);
	}

	/***
	 * Return the file name of this part.
	 * @return The name.
	 */
	public String getFileName() {
		return source.getFileName();
	}

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name of the file part
	 * @param file the file to post
	 *
	 * @throws FileNotFoundException if the <i>file</i> is not a normal
	 * file or if it is not readable.
	 */
	public FilePart(String name, File file) 
			throws FileNotFoundException {
		this(name, new FilePartSource(file), null, null);
	}

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name of the file part
	 * @param file the file to post
	 * @param contentType the content type for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CONTENT_TYPE default} is used
	 * @param charset the charset encoding for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CHARSET default} is used
	 *
	 * @throws FileNotFoundException if the <i>file</i> is not a normal
	 * file or if it is not readable.
	 */
	public FilePart(String name, File file, String contentType, String charset) 
			throws FileNotFoundException {
		this(name, new FilePartSource(file), contentType, charset);
	}

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name of the file part
	 * @param fileName the file name 
	 * @param file the file to post
	 *
	 * @throws FileNotFoundException if the <i>file</i> is not a normal
	 * file or if it is not readable.
	 */
	public FilePart(String name, String fileName, File file) 
			throws FileNotFoundException {
		this(name, new FilePartSource(fileName, file), null, null);
	}

	/***
	 * FilePart Constructor.
	 *
	 * @param name the name of the file part
	 * @param fileName the file name 
	 * @param file the file to post
	 * @param contentType the content type for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CONTENT_TYPE default} is used
	 * @param charset the charset encoding for this part, if <code>null</code> the 
	 * {@link #DEFAULT_CHARSET default} is used
	 *
	 * @throws FileNotFoundException if the <i>file</i> is not a normal
	 * file or if it is not readable.
	 */
	public FilePart(String name, String fileName, File file, String contentType, String charset) 
			throws FileNotFoundException {
		this(name, new FilePartSource(fileName, file), contentType, charset);
	}

	/***
	 * Write the disposition header to the output stream
	 * @param out The output stream
	 * @throws IOException If an IO problem occurs
	 * @see Part#sendDispositionHeader(OutputStream)
	 */
	@Override
	protected void sendDispositionHeader(OutputStream out) 
			throws IOException {
		Logger.d(TAG,"enter sendDispositionHeader(OutputStream out)");
		super.sendDispositionHeader(out);
		String filename = this.source.getFileName();
		if (filename != null) {
			out.write(FILE_NAME_BYTES);
			out.write(QUOTE_BYTES);
			out.write(EncodingUtils.getAsciiBytes(filename));
			out.write(QUOTE_BYTES);
		}
	}

	/***
	 * Write the data in "source" to the specified stream.
	 * @param out The output stream.
	 * @throws IOException if an IO problem occurs.
	 * @see Part#sendData(OutputStream)
	 */
	@Override
	protected void sendData(OutputStream out) throws IOException {
		Logger.d(TAG,"enter sendData(OutputStream out)");
		if (lengthOfData() == 0) {

			// this file contains no data, so there is nothing to send.
			// we don't want to create a zero length buffer as this will
			// cause an infinite loop when reading.
			Logger.d(TAG,"No data to send.");
			return;
		}

		byte[] tmp = new byte[4096];
		InputStream instream = source.createInputStream();
		try {
			int len;
			while ((len = instream.read(tmp)) >= 0) {
				out.write(tmp, 0, len);
			}
		} finally {
			// we're done with the stream, close it
			instream.close();
		}
	}

	/*** 
	 * Returns the source of the file part.
	 *  
	 * @return The source.
	 */
	protected PartSource getSource() {
		Logger.d(TAG,"enter getSource()");
		return this.source;
	}

	/***
	 * Return the length of the data.
	 * @return The length.
	 * @see Part#lengthOfData()
	 */    
	@Override
	protected long lengthOfData() {
		Logger.d(TAG,"enter lengthOfData()");
		return source.getLength();
	}    

}

